/*
 * FreeRTOS V202212.00
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * https://www.FreeRTOS.org
 * https://github.com/FreeRTOS
 *
 */

/******************************************************************************
 * NOTE 1:  This project provides two demo applications.  A simple blinky style
 * project, and a more comprehensive test and demo application.  The
 * mainCREATE_SIMPLE_BLINKY_DEMO_ONLY setting in main.c is used to select
 * between the two.  See the notes on using mainCREATE_SIMPLE_BLINKY_DEMO_ONLY
 * in main.c.  This file implements the comprehensive test and demo version.
 *
 * NOTE 2:  This file only contains the source code that is specific to the
 * full demo.  Generic functions, such FreeRTOS hook functions, and functions
 * required to configure the hardware, are defined in main.c.
 ******************************************************************************
 *
 * main_full() creates all the demo application tasks and software timers, then
 * starts the scheduler.  The WEB documentation provides more details of the
 * standard demo application tasks.  In addition to the standard demo tasks, the
 * following tasks and tests are defined and/or created within this file:
 *
 * "LCD" task - the LCD task is a 'gatekeeper' task.  It is the only task that
 * is permitted to access the display directly.  Other tasks wishing to write a
 * message to the LCD send the message on a queue to the LCD task instead of
 * accessing the LCD themselves.  The LCD task just blocks on the queue waiting
 * for messages - waking and displaying the messages as they arrive.
 * **NOTE** The LCD driver has a dependency on the PLIB library, which is no
 * longer provided by Microchip, so LCD functionality has been removed from this
 * demo - however the source files remain in the distribution.
 *
 * "Check" timer - The check software timer period is initially set to three
 * seconds.  The callback function associated with the check software timer
 * checks that all the standard demo tasks, and the register check tasks, are
 * not only still executing, but are executing without reporting any errors.  If
 * the check software timer discovers that a task has either stalled, or
 * reported an error, then it changes its own execution period from the initial
 * three seconds, to just 200ms.  The check software timer callback function
 * also writes a status message to the LCD (via the LCD task).  If all the demo
 * tasks are executing with their expected behaviour then the check task writes
 * a count of the number of times the high frequency interrupt has incremented
 * ulHighFrequencyTimerInterrupts - which is one in every 20,000 interrupts.
 *
 * "Register test" tasks - These tasks are used in part to test the kernel port.
 * They set each processor register to a known value, then check that the
 * register still contains that value.  Each of the tasks sets the registers
 * to different values, and will get swapping in and out between setting and
 * then subsequently checking the register values.  Discovery of an incorrect
 * value would be indicative of an error in the task switching mechanism.
 *
 * By way of demonstration, the demo application defines
 * configMAX_SYSCALL_INTERRUPT_PRIORITY to be 3, configKERNEL_INTERRUPT_PRIORITY
 * to be 1, and all other interrupts as follows:
 *
 *	+ The UART is allocated a priority of 2. This means it can interrupt the
 *    RTOS tick, and can also safely use queues.
 *    **NOTE** The UART driver has a dependency on the PLIB library, which is no
 *    longer provided by Microchip, so UART functionality has been removed from
 *    this demo - however the source files remain in the distribution.
 *
 *  + Two timers are configured to generate interrupts just to test the nesting
 *    and queue access mechanisms. These timers are allocated priorities 2 and 3
 *    respectively. Even though they both access the same two queues, the
 *    priority 3 interrupt can safely interrupt the priority 2 interrupt. Both
 *    can interrupt the RTOS tick.
 *  + Finally a high frequency timer interrupt is configured to use priority 4 -
 *    therefore kernel activity will never prevent the high frequency timer from
 *    executing immediately that the interrupt is raised (within the limitations
 *    of the hardware itself). It would not be safe to access a queue from this
 *    interrupt as it is above configMAX_SYSCALL_INTERRUPT_PRIORITY.
 *
 * See the online documentation for this demo for more information on interrupt
 * usage.
 */

/* Standard includes. */
#include <stdio.h>

/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "timers.h"

/* Demo application includes. */
#include "partest.h"
#include "blocktim.h"
#include "flash_timer.h"
#include "semtest.h"
#include "GenQTest.h"
#include "QPeek.h"
#include "lcd.h"
#include "timertest.h"
#include "IntQueue.h"

/*-----------------------------------------------------------*/

/* The period after which the check timer will expire, in ms, provided no errors
 * have been reported by any of the standard demo tasks.  ms are converted to the
 * equivalent in ticks using the portTICK_PERIOD_MS constant. */
#define mainCHECK_TIMER_PERIOD_MS                 ( 3000UL / portTICK_PERIOD_MS )

/* The period at which the check timer will expire, in ms, if an error has been
 * reported in one of the standard demo tasks.  ms are converted to the equivalent
 * in ticks using the portTICK_PERIOD_MS constant. */
#define mainERROR_CHECK_TIMER_PERIOD_MS           ( 200UL / portTICK_PERIOD_MS )

/* The priorities of the various demo application tasks. */
#define mainSEM_TEST_PRIORITY                     ( tskIDLE_PRIORITY + 1 )
#define mainBLOCK_Q_PRIORITY                      ( tskIDLE_PRIORITY + 2 )
#define mainCOM_TEST_PRIORITY                     ( tskIDLE_PRIORITY + 2 )
#define mainINTEGER_TASK_PRIORITY                 ( tskIDLE_PRIORITY )
#define mainGEN_QUEUE_TASK_PRIORITY               ( tskIDLE_PRIORITY )

/* Misc. */
#define mainDONT_BLOCK                            ( 0 )

/* Dimension the buffer used to hold the value of the high frequency timer
 * count when it is converted to a string. */
#define mainMAX_STRING_LENGTH                     ( 20 )

/* The frequency at which the "fast interrupt test" interrupt will occur. */
#define mainTEST_INTERRUPT_FREQUENCY              ( 20000 )

/* The number of timer clocks expected to occur between each "fast interrupt
 * test" interrupt. */
#define mainEXPECTED_CLOCKS_BETWEEN_INTERRUPTS    ( ( configCPU_CLOCK_HZ >> 1 ) / mainTEST_INTERRUPT_FREQUENCY )

/* The number of nano seconds between each core clock. */
#define mainNS_PER_CLOCK                          ( ( unsigned long ) ( ( 1.0 / ( double ) ( configCPU_CLOCK_HZ >> 1 ) ) * 1000000000.0 ) )

/* The number of LEDs that should be controlled by the flash software timer
 * standard demo and the LED to be toggle by the check task.  The starter kit only
 * has three LEDs so when the demo is configured to run on the starter kit there
 * is one less flash timer so the check task can use the third LED. */
#ifdef PIC32_STARTER_KIT
    #define mainNUM_FLASH_TIMER_LEDS    ( 2 )
    #define mainCHECK_LED               ( 2 )
#else
    #define mainNUM_FLASH_TIMER_LEDS    ( 3 )
    #define mainCHECK_LED               ( 7 )
#endif

/*-----------------------------------------------------------*/

/*
 * The check timer callback function, as described at the top of this file.
 */
static void prvCheckTimerCallback( TimerHandle_t xTimer );

/*
 * It is important to ensure the high frequency timer test does not start before
 * the kernel.  It is therefore started from inside a software timer callback
 * function, which will not execute until the timer service/daemon task is
 * executing.  A one-shot timer is used, so the callback function will only
 * execute once (unless it is manually reset/restarted).
 */
static void prvSetupHighFrequencyTimerTest( TimerHandle_t xTimer );

/*
 * Tasks that test the context switch mechanism by filling the processor
 * registers with known values, then checking that the values contained
 * within the registers is as expected.  The tasks are likely to get swapped
 * in and out between setting the register values and checking the register
 * values.
 */
static void prvRegTestTask1( void * pvParameters );
static void prvRegTestTask2( void * pvParameters );

/*-----------------------------------------------------------*/

/* The queue used to send messages to the LCD task. */
static QueueHandle_t xLCDQueue;

/* Variables incremented by prvRegTestTask1() and prvRegTestTask2() respectively on
 * each iteration of their function.  This is used to detect either task stopping
 * their execution.. */
volatile unsigned long ulRegTest1Cycles = 0, ulRegTest2Cycles = 0;

/*-----------------------------------------------------------*/

/*
 * Create the demo tasks then start the scheduler.
 */
int main_full( void )
{
    TimerHandle_t xTimer = NULL;

    /* Create all the other standard demo tasks. */
    vStartLEDFlashTimers( mainNUM_FLASH_TIMER_LEDS );
    vCreateBlockTimeTasks();
    vStartSemaphoreTasks( mainSEM_TEST_PRIORITY );
    vStartGenericQueueTasks( mainGEN_QUEUE_TASK_PRIORITY );
    vStartQueuePeekTasks();
    vStartInterruptQueueTasks();

    /* Create the tasks defined within this file. */
    xTaskCreate( prvRegTestTask1, "Reg1", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
    xTaskCreate( prvRegTestTask2, "Reg2", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );

    /* Create the software timer that performs the 'check' functionality, as
     * described at the top of this file. */
    xTimer = xTimerCreate( "CheckTimer",                  /* A text name, purely to help debugging. */
                           ( mainCHECK_TIMER_PERIOD_MS ), /* The timer period, in this case 3000ms (3s). */
                           pdTRUE,                        /* This is an auto-reload timer, so xAutoReload is set to pdTRUE. */
                           ( void * ) 0,                  /* The ID is not used, so can be set to anything. */
                           prvCheckTimerCallback          /* The callback function that inspects the status of all the other tasks. */
                           );

    if( xTimer != NULL )
    {
        xTimerStart( xTimer, mainDONT_BLOCK );
    }

    /* A software timer is also used to start the high frequency timer test.
     * This is to ensure the test does not start before the kernel.  This time a
     * one-shot software timer is used. */
    xTimer = xTimerCreate( "HighHzTimerSetup", 1, pdFALSE, ( void * ) 0, prvSetupHighFrequencyTimerTest );

    if( xTimer != NULL )
    {
        xTimerStart( xTimer, mainDONT_BLOCK );
    }

    /* Finally start the scheduler. */
    vTaskStartScheduler();

    /* If all is well, the scheduler will now be running, and the following line
     * will never be reached.  If the following line does execute, then there was
     * insufficient FreeRTOS heap memory available for the idle and/or timer tasks
     * to be created.  See the memory management section on the FreeRTOS web site
     * for more details. */
    for( ; ; )
    {
    }
}
/*-----------------------------------------------------------*/

static void prvRegTestTask1( void * pvParameters )
{
    extern void vRegTest1( volatile unsigned long * );

    /* Avoid compiler warnings. */
    ( void ) pvParameters;

    /* Pass the address of the RegTest1 loop counter into the test function,
     * which is necessarily implemented in assembler. */
    vRegTest1( &ulRegTest1Cycles );

    /* vRegTest1 should never exit! */
    vTaskDelete( NULL );
}
/*-----------------------------------------------------------*/

static void prvRegTestTask2( void * pvParameters )
{
    extern void vRegTest2( volatile unsigned long * );

    /* Avoid compiler warnings. */
    ( void ) pvParameters;

    /* Pass the address of the RegTest2 loop counter into the test function,
     * which is necessarily implemented in assembler. */
    vRegTest2( &ulRegTest2Cycles );

    /* vRegTest1 should never exit! */
    vTaskDelete( NULL );
}
/*-----------------------------------------------------------*/

static void prvCheckTimerCallback( TimerHandle_t xTimer )
{
    static long lChangedTimerPeriodAlready = pdFALSE;
    static unsigned long ulLastRegTest1Value = 0, ulLastRegTest2Value = 0;

/* Buffer into which the high frequency timer count is written as a string. */
    static char cStringBuffer[ mainMAX_STRING_LENGTH ];

/* The count of the high frequency timer interrupts. */
    extern unsigned long ulHighFrequencyTimerInterrupts;
    static xLCDMessage xMessage = { ( 200 / portTICK_PERIOD_MS ), cStringBuffer };

    /* Check that the register test 1 task is still running. */
    if( ulLastRegTest1Value == ulRegTest1Cycles )
    {
        xMessage.pcMessage = "Error: Reg test2";
    }

    ulLastRegTest1Value = ulRegTest1Cycles;

    /* Check that the register test 2 task is still running. */
    if( ulLastRegTest2Value == ulRegTest2Cycles )
    {
        xMessage.pcMessage = "Error: Reg test3";
    }

    ulLastRegTest2Value = ulRegTest2Cycles;

    /* Have any of the standard demo tasks detected an error in their
     * operation? */
    if( xAreGenericQueueTasksStillRunning() != pdTRUE )
    {
        xMessage.pcMessage = "Error: Gen Q";
    }
    else if( xAreQueuePeekTasksStillRunning() != pdTRUE )
    {
        xMessage.pcMessage = "Error: Q Peek";
    }
    else if( xAreBlockTimeTestTasksStillRunning() != pdTRUE )
    {
        xMessage.pcMessage = "Error: Blck time";
    }
    else if( xAreSemaphoreTasksStillRunning() != pdTRUE )
    {
        xMessage.pcMessage = "Error: Sem test";
    }
    else if( xAreIntQueueTasksStillRunning() != pdTRUE )
    {
        xMessage.pcMessage = "Error: Int queue";
    }

    if( xMessage.pcMessage != cStringBuffer )
    {
        /* An error string has been logged.  If the timer period has not yet
         * been changed it should be changed now.  Increasing the frequency of the
         * LED gives visual feedback of the error status. */
        if( lChangedTimerPeriodAlready == pdFALSE )
        {
            lChangedTimerPeriodAlready = pdTRUE;

            /* This call to xTimerChangePeriod() uses a zero block time.
             * Functions called from inside of a timer callback function must
             * never* attempt	to block as to do so could impact other software
             * timers. */
            xTimerChangePeriod( xTimer, ( mainERROR_CHECK_TIMER_PERIOD_MS ), mainDONT_BLOCK );
        }
    }
    else
    {
        /* Write the ulHighFrequencyTimerInterrupts value to the string
         * buffer.  It will only be displayed if no errors have been detected. */
        sprintf( cStringBuffer, "Pass %u", ( unsigned int ) ulHighFrequencyTimerInterrupts );
    }

    vParTestToggleLED( mainCHECK_LED );
}
/*-----------------------------------------------------------*/

static void prvSetupHighFrequencyTimerTest( TimerHandle_t xTimer )
{
    /* Setup the high frequency, high priority, timer test.  It is setup in this
     * software timer callback to ensure it does not start before the kernel does.
     * This is a one-shot timer - so the setup routine will only be executed once. */
    vSetupTimerTest( mainTEST_INTERRUPT_FREQUENCY );
}
